sql性能相关语句

1.查看消耗资源最多的SQL

 SELECT hash_value, executions, buffer_gets, disk_reads, parse_calls,sql_fulltext
 FROM V$SQLAREA
 WHERE buffer_gets > 10000000 OR disk_reads > 1000000
 ORDER BY buffer_gets + 100 * disk_reads DESC;

2.查看某条SQL语句的资源消耗

 SELECT hash_value, buffer_gets, disk_reads, executions, parse_calls
 FROM V$SQLAREA
 WHERE hash_Value = 228801498 AND address = hextoraw('CBD8E4B0');

3.查找前十条性能差的SQL语句

 SELECT * FROM (select PARSING_USER_ID,EXECUTIONS,SORTS,COMMAND_TYPE,DISK_READS,sql_text FROM v$sqlarea
 order BY disk_reads DESC )where ROWNUM<10 ;